Create a FracSec from the given units ("msecs", "usecs", or "hnsecs").
The units to create a FracSec from.
The number of the given units passed the second.
TimeException if the given value would result in a FracSec greater than or equal to 1 second or less than or equal to -1 seconds.
Create a FracSec from the given units ("msecs", "usecs", or "hnsecs").